To test the hypothesis that while bedtime administrations of a snack, alanine (which has epinephrine-like actions) prevent hypoglycemia during the first half of the night, only bedtime alanine, terbutaline, or both support glycemia during the second half of the night, patients with IDDM are studied on 4 occasions. NPH insulin and either no treatment or a snack (1240ml 2% milk & 1 piece of toast), alanine 40g with glucose 10g p.o. or terbutaline 5.0 mg p.o., in random sequence are given at 2200 hours and plasma glucose measured serially through 0700 hours.